Method for error suppression of inertial concretionary coarse alignment of strapdown inertial navigation system

Abstract

The invention relates to a method for error suppression of inertial concretionary coarse alignment of a strapdown inertial navigation system and belongs to the technical field of inertial navigation. The method comprises the following steps of 1, according to current longitude and latitude of a carrier, carrying out transformation of an earth coordinate system into a navigation coordinate system, 2, driving two shafts of a rotation-type inertial navigation system to periodically rotate according to a certain rotating scheme, 3, according to angular velocity information output by a gyroscope in coarse alignment, updating a direction cosine matrix of a posture change of an inertial measurement unit (IMU) coordinate system relative to a p0 coordinate system through calculating a numerical solution of a matrix differential equation, and 4, orderly calculating solutions of matrixes to obtain a posture matrix of the carrier so that coarse alignment is finished. The method has the advantages that through an integral operation in coarse alignment, swinging and shaking-caused error components of outputs of an accelerometer of a ship in alignment of storm-caused swinging and shaking can be compensated; and through IMU double-shaft rotation modulation, an accelerometer zero-bias error accumulated over time is suppressed so that the precision of inertial concretionary coarse alignment is improved.

Description

technical field The invention relates to an error suppression method for a rough alignment method of a solidified inertial system of a strapdown inertial navigation system under the condition of a oscillating and swaying base, and belongs to the technical field of inertial navigation. Background technique The initial alignment technology of the strapdown inertial navigation system is to determine the initial position of the carrier, the initial velocity, and the initial attitude angle and direction cosine matrix or initial quaternion from the carrier coordinate system to the navigation coordinate system with a certain accuracy in a short period of time. number. For the carrier without linear motion, its position can be obtained through the external information of the carrier (such as GNSS positioning data), and directly bound into the navigation computer. When the ground speed is zero when the carrier has no linear motion, it can also be directly bound into the navigation co...

AI Technical Summary

Problems solved by technology

The purpose of the present invention is to solve the technical problem that the zero offset error component output by the accelerometer accumulates over time in the coarse alignment method of the solidified inertial system, which causes the accuracy of the coarse alignment to decrease, and to provide a rotary strapdown inertial navigation system through a rotary inertial measurement unit (IMU) modulating the accelerometer zero bias error, thereby improving the accuracy of the solidification inertial frame coarse alignment method